839 research outputs found
Bounding the dimensions of rational cohomology groups
Let be an algebraically closed field of characteristic , and let
be a simple simply-connected algebraic group over that is defined and
split over the prime field . In this paper we investigate
situations where the dimension of a rational cohomology group for can be
bounded by a constant times the dimension of the coefficient module. We then
demonstrate how our results can be applied to obtain effective bounds on the
first cohomology of the symmetric group. We also show how, for finite Chevalley
groups, our methods permit significant improvements over previous estimates for
the dimensions of second cohomology groups.Comment: 13 page
Pharmacologic Targeting of Bacterial  -Glucuronidase Alleviates Nonsteroidal Anti-Inflammatory Drug-Induced Enteropathy in Mice
Small intestinal mucosal injury is a frequent adverse effect caused by nonsteroidal anti-inflammatory drugs (NSAIDs). The underlying mechanisms are not completely understood, but topical (luminal) effects have been implicated. Many carboxylic acid-containing NSAIDs, including diclofenac (DCF), are metabolized to acyl glucuronides (AGs), and/or ether glucuronides after ring hydroxylation, and exported into the biliary tree. In the gut, these conjugates are cleaved by bacterial ÎČ-glucuronidase, releasing the potentially harmful aglycone. We first confirmed that DCF-AG was an excellent substrate for purified Escherichia coli ÎČ-d-glucuronidase. Using a previously characterized novel bacteria-specific ÎČ-glucuronidase inhibitor (Inhibitor-1), we then found that the enzymatic hydrolysis of DCF-AG in vitro was inhibited concentration dependently (IC50 âŒ164 nM). We next hypothesized that pharmacologic inhibition of bacterial ÎČ-glucuronidase would reduce exposure of enterocytes to the aglycone and, as a result, alleviate enteropathy. C57BL/6J mice were administered an ulcerogenic dose of DCF (60 mg/kg i.p.) with or without oral pretreatment with Inhibitor-1 (10 ÎŒg per mouse, b.i.d.). Whereas DCF alone caused the formation of numerous large ulcers in the distal parts of the small intestine and increased (2-fold) the intestinal permeability to fluorescein isothiocyanate-dextran, Inhibitor-1 cotreatment significantly alleviated mucosal injury and reduced all parameters of enteropathy. Pharmacokinetic profiling of DCF plasma levels in mice revealed that Inhibitor-1 coadministration did not significantly alter the Cmax, half-life, or area under the plasma concentration versus time curve of DCF. Thus, highly selective pharmacologic targeting of luminal bacterial ÎČ-d-glucuronidase by a novel class of small-molecule inhibitors protects against DCF-induced enteropathy without altering systemic drug exposure
Building better Sex Robots: Lessons from Feminist Pornography
How should we react to the development of sexbot technology? Taking their cue from anti-porn feminism, several academic critics lament the development of sexbot technology, arguing that it objectifies and subordinates women, is likely to promote misogynistic attitudes toward sex, and may need to be banned or restricted. In this chapter I argue for an alternative response. Taking my cue from the sex positive âfeminist pornâ movement, I argue that the best response to the development of âbadâ sexbots is to make better ones. This will require changes to the content, process and context of sexbot development. Doing so will acknowledge the valuable role that technology can play in human sexuality, and allow us to challenge gendered norms and assumptions about male and female sexual desire. This will not be a panacea to the social problems that could arise from sexbot development, but it offers a more realistic and hopeful vision for the future of this technology in a pluralistic and progressive society
Neurofilament light compared to neuron-specific enolase as a predictor of unfavourable outcome after out-of-hospital cardiac arrest
Aim: We compared the prognostic abilities of neurofilament light (NfL) and neuron-specific enolase (NSE) in patients resuscitated from out-ofhospital cardiac arrest (OHCA) of various aetiologies. Methods: We analysed frozen blood samples obtained at 24 and 48 hours from OHCA patients treated in 21 Finnish intensive care units in 2010 and 2011. We defined unfavourable outcome as Cerebral Performance Category (CPC) 3-5 at 12 months after OHCA. We evaluated the prognostic ability of the biomarkers by calculating the area under the receiver operating characteristic curves (AUROCs [95% confidence intervals]) and compared these with a bootstrap method. Results: Out of 248 adult patients, 12-month outcome was unfavourable in 120 (48.4%). The median (interquartile range) NfL concentrations for patients with unfavourable and those with favourable outcome, respectively, were 689 (146-1804) pg/mL vs. 31 (17-61) pg/mL at 24 h and 1162 (147-4360) pg/mL vs. 36 (21-87) pg/mL at 48 h, p < 0.001 for both. The corresponding NSE concentrations were 13.3 (7.2-27.3) mg/L vs. 8.5 (5.8- 13.2) mg/L at 24 h and 20.4 (8.1-56.6) mg/L vs. 8.2 (5.9-12.1) mg/L at 48 h, p < 0.001 for both. The AUROCs to predict an unfavourable outcome were 0.90 (0.86-0.94) for NfL vs. 0.65 (0.58-0.72) for NSE at 24 h, p < 0.001 and 0.88 (0.83-0.93) for NfL and 0.73 (0.66-0.81) for NSE at 48 h, p < 0.001. Conclusion: Compared to NSE, NfL demonstrated superior accuracy in predicting long-term unfavourable outcome after OHCA.Peer reviewe
Nutritional and socio-economic determinants of cognitive function and educational achievement of Aboriginal schoolchildren in rural Malaysia
A community-based cross-sectional study was carried out among Aboriginal schoolchildren aged 7â12 years living in remote areas in Pos Betau, Pahang, Malaysia to investigate the potential determinants influencing the cognitive function and educational achievement of these children. Cognitive function was measured by intelligence quotient (IQ), while examination scores of selected school subjects were used in assessing educational achievement. Blood samples were collected to assess serum Fe status. All children were screened for soil-transmitted helminthes. Demographic and socio-economic data were collected using pre-tested questionnaires. Almost two-thirds (67·6 %) of the subjects had poor IQ and most of them (72·6 %) had insufficient educational achievement. Output of the stepwise multiple regression model showed that poor IQ was significantly associated with low household income which contributed the most to the regression variance (r2 0·059; P = 0·020). Low maternal education was also identified as a significant predictor of low IQ scores (r2 0·042; P = 0·043). With educational achievement, Fe-deficiency anaemia (IDA) was the only variable to show significant association (r2 0·025; P = 0·015). In conclusion, the cognitive function and educational achievement of Aboriginal schoolchildren are poor and influenced by household income, maternal education and IDA. Thus, effective and integrated measures to improve the nutritional and socio-economic status of rural children would have a pronounced positive effect on their education
Ptch2/Gas1 and Ptch1/Boc differentially regulate Hedgehog signalling in murine primordial germ cell migration.
Gas1 and Boc/Cdon act as co-receptors in the vertebrate Hedgehog signalling pathway, but the nature of their interaction with the primary Ptch1/2 receptors remains unclear. Here we demonstrate, using primordial germ cell migration in mouse as a developmental model, that specific hetero-complexes of Ptch2/Gas1 and Ptch1/Boc mediate the process of Smo de-repression with different kinetics, through distinct modes of Hedgehog ligand reception. Moreover, Ptch2-mediated Hedgehog signalling induces the phosphorylation of Creb and Src proteins in parallel to Gli induction, identifying a previously unknown Ptch2-specific signal pathway. We propose that although Ptch1 and Ptch2 functionally overlap in the sequestration of Smo, the spatiotemporal expression of Boc and Gas1 may determine the outcome of Hedgehog signalling through compartmentalisation and modulation of Smo-downstream signalling. Our study identifies the existence of a divergent Hedgehog signal pathway mediated by Ptch2 and provides a mechanism for differential interpretation of Hedgehog signalling in the germ cell niche
A descriptive study of the surge response and outcomes of ICU patients with COVID-19 during first wave in Nordic countries
Abstract Background We sought to provide a description of surge response strategies and characteristics, clinical management and outcomes of patients with severe COVID-19 in the intensive care unit (ICU) during the first wave of the pandemic in Denmark, Finland, Iceland, Norway and Sweden. Methods Representatives from the national ICU registries for each of the five countries provided clinical data and a description of the strategies to allocate ICU resources and increase the ICU capacity during the pandemic. All adult patients admitted to the ICU for COVID-19 disease during the first wave of COVID-19 were included. The clinical characteristics, ICU management and outcomes of individual countries were described with descriptive statistics. Results Most countries more than doubled their ICU capacity during the pandemic. For patients positive for SARS-CoV-2, the ratio of requiring ICU admission for COVID-19 varied substantially (1.6-6.7%). Apart from age (proportion of patients aged 65 years or over between 29-62%), baseline characteristics, chronic comorbidity burden and acute presentations of COVID-19 disease were similar among the five countries. While utilization of invasive mechanical ventilation was high (59-85%) in all countries, the proportion of patients receiving renal replacement therapy (7-26%) and various experimental therapies for COVID-19 disease varied substantially (e.g. use of hydroxychloroquine 0-85%). Crude ICU mortality ranged from 11% to 33%. Conclusion There was substantial variability in the critical care response in Nordic ICUs to the first wave of COVID-19 pandemic, including usage of experimental medications. While ICU mortality was low in all countries, the observed variability warrants further attention.Peer reviewe
Inhibition of breathing after surfactant depletion is achieved at a higher arterial PCO(2 )during ventilation with liquid than with gas
BACKGROUND: Inhibition of phrenic nerve activity (PNA) can be achieved when alveolar ventilation is adequate and when stretching of lung tissue stimulates mechanoreceptors to inhibit inspiratory activity. During mechanical ventilation under different lung conditions, inhibition of PNA can provide a physiological setting at which ventilatory parameters can be compared and related to arterial blood gases and pH. OBJECTIVE: To study lung mechanics and gas exchange at inhibition of PNA during controlled gas ventilation (GV) and during partial liquid ventilation (PLV) before and after lung lavage. METHODS: Nine anaesthetised, mechanically ventilated young cats (age 3.8 ± 0.5 months, weight 2.3 ± 0.1 kg) (mean ± SD) were studied with stepwise increases in peak inspiratory pressure (PIP) until total inhibition of PNA was attained before lavage (with GV) and after lavage (GV and PLV). Tidal volume (V(t)), PIP, oesophageal pressure and arterial blood gases were measured at inhibition of PNA. One way repeated measures analysis of variance and Student Newman Keuls-tests were used for statistical analysis. RESULTS: During GV, inhibition of PNA occurred at lower PIP, transpulmonary pressure (Ptp) and Vt before than after lung lavage. After lavage, inhibition of inspiratory activity was achieved at the same PIP, Ptp and Vt during GV and PLV, but occurred at a higher PaCO(2 )during PLV. After lavage compliance at inhibition was almost the same during GV and PLV and resistance was lower during GV than during PLV. CONCLUSION: Inhibition of inspiratory activity occurs at a higher PaCO(2 )during PLV than during GV in cats with surfactant-depleted lungs. This could indicate that PLV induces better recruitment of mechanoreceptors than GV
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
Association of endothelial and glycocalyx injury biomarkers with fluid administration, development of acute kidney injury, and 90-day mortality: data from the FINNAKI observational study
Background Injury to endothelium and glycocalyx predisposes to vascular leak, which may subsequently lead to increased fluid requirements and worse outcomes. In this post hoc study of the prospective multicenter observational Finnish Acute Kidney Injury (FINNAKI) cohort study conducted in 17 Finnish intensive care units, we studied the association of Syndecan-1 (SDC-1), Angiopoetin-2 (Ang-2), soluble thrombomodulin (sTM), vascular adhesion protein-1 (VAP-1) and interleukin-6 (IL-6) with fluid administration and balance among septic critical care patients and their association with development of acute kidney injury (AKI) and 90-day mortality. Results SDC-1, Ang-2, sTM, VAP-1 and IL-6 levels were measured at ICU admission from 619 patients with sepsis. VAP-1 decreased (p 12 h from ICU admission (AKI(>12 h)). They had higher sTM levels than patients without AKI, and after multivariable adjustment log, sTM level was associated with AKI(>12 h) with OR (95% CI) of 12.71 (2.96-54.67), p = 0.001). Ninety-day non-survivors (n = 180; 29.1%) had higher SDC-1 and sTM levels compared to survivors. After adjustment for known confounders, log SDC-1 (OR [95% CI] 2.13 [1.31-3.49], p = 0.002), log sTM (OR [95% CI] 7.35 [2.29-23.57], p < 0.001), and log Ang-2 (OR [95% CI] 2.47 [1.44-4.14], p = 0.001) associated with an increased risk for 90-day mortality. Finally, patients who had high levels of all three markers, namely, SDC-1, Ang-2 and sTM, had an adjusted OR of 5.61 (95% CI 2.67-11.79; p < 0.001) for 90-day mortality. Conclusions VAP-1 and IL-6 associated with fluid administration on the first ICU day. After adjusting for confounders, sTM was associated with development of AKI after 12 h from ICU admission. SDC-1, Ang-2 and sTM were independently associated with an increased risk for 90-day mortality
- âŠ